I used to work music retail, so I got a lot of backstage passes, and some in-store appearances I used to work. So "meeting" someone famous backstage is different from being able to sit down and talk with them.
Backstage, I had met all the members of Kansas, Yes, Styx, and a couple of others not worth even mentioning.
But at in-stores, I've had extended conversations with a few members of Kansas, Steve Howe, Yngwie Malmsteen and Joe Lynn Turner. Joe Lynn was a very cool guy.